1. Field of the Invention
This invention relates to an electrical connector assembly which exhibits zero insertion force for a printed circuit board, liquid crystal plate, or like contact carriers.
2. Description of the Prior Art
The conventional manner for making electrical connection to a plate-like contact carrier, for example a printed circuit board or liquid crystal plate, is by way of a connector body having an elongated slot therein, and a plurality of spring contacts adapted to apply pressure against the contact carrier when the latter is inserted in the slot to both attain the necessary electrical contact quality and to mechanically support the circuit board. Such connectors are either rack mounted in an electronic instrument with the circuit board insertable therein and removable therefrom, or the connector may be a portion of the printed circuit board itself being soldered thereto and insertable over a contact carrier mounted in the electronic equipment.
Normally, a contact carrier which is to be connected is inserted into the connector slot between the spring contacts until it hits a stop, and inserting the boards in this manner results in a sometimes desirable sliding contact between the conductive fingers on the board and the spring contacts of the connector. However, there are certain contact carriers which are extremely thin or which have conductive fingers that are not sufficiently scratch proof, so that a sliding of the contact carrier into the connector causes damage to the carrier itself or its conductive fingers. For example, the conductive fingers of a liquid crystal glass plate usually have only a thickness of about 0.01mm. Such fingers would be destroyed during the sliding motion into a conventional connector due to the necessarily high mechanical biasing force of the contact springs.
A connector is known which is so constructed that a contact carrier can be positioned with its conductive fingers adjacent the spring contacts, and then, in order to effect sufficient contact pressure, a separate member is inserted into the connector body to press the contact carrier against the contacts. A frame surrounding the contact carrier insures that the carrier cannot be laterally removed from the connector. A disadvantage resulting from this construction, however, is that the contact carrier is mechanically supported only by the spring force of the contacts within the area where the carrier is inserted into the connector. Thus, in assembling, handling, and shipping of the equipment, it would be easily possible to move the contact carrier within the connector back and forth within certain limits, thereby damaging the carrier and/or conductive fingers due to the rubbing of the spring contacts against the delicate conductive fingers and possibly contact carrier.